This invention relates to a unitary micro-flexure structure, and to a method of making the same. A preferred embodiment of the invention is described herein in a setting wherein the invention finds particular applicability, and namely in the setting of an electromagnetic read/write structure for the reading and writing of magnetic images on and with respect to a relatively moving magnetic recording medium, such as a disk or drum. Thus, and in the setting of this read/write application, the invention relates to a unique, unitary, elongate, integrated read/write head/flexure/conductor cantilever structure of extremely small size, which structure includes an elongate flexure body with a stretch which is specially formed, as by ablation (laser and/or reactive-ion and/or chemical etching) and in certain modifications progressively diminished in cross section, e.g., tapered, in the direction from the body's mounting end toward its free end.
The structure of this invention, in the read/write setting expressed above, offers, in certain applications, decided improvements in dynamic mechanical performance over generically similar structures which are disclosed in four of my prior-filed U.S. Patents Applications: Ser. Nos. 07/441,716, filed Nov. 27, 1989, for "INTEGRATED MAGNETIC READ/WRITE HEAD/FLEXURE/CONDUCTOR STRUCTURE", 07/632,958, filed Dec. 21, 1990, for "METHOD OF MAKING INTEGRATED MAGNETIC READ/WRITE HEAD/FLEXURE/CONDUCTOR STRUCTURE" (as amended), 07/710,561, filed Jun. 5, 1991, for "INTEGRATED MAGNETIC READ/WRITE HEAD/FLEXURE/CONDUCTOR STRUCTURE", and 07/710,891, filed Jun. 11, 1991 for "INTEGRATED MAGNETIC READ/WRITE HEAD/FLEXURE/CONDUCTOR STRUCTURE". Much of the important background of the invention disclosed and claimed herein, as well as a fully detailed description of read/write-application internal electromagnetic structure, and of preferred fabrication methodology, are found in those prior-filed applications, and accordingly, and in order to avoid unnecessary, detailed repetition herein, the entire contents of these four referenced patent applications are hereby incorporated by reference.
In the structure disclosed in these earlier application documents, an elongate flexure body is illustrated which has a substantially uniform cross-sectional area, and lateral dimension, along nearly all of its length, extending between its mounting end and its free, magnetic-"head-carrying" end. Such construction has been proven to offer wide, successful applicability in many read/write systems applications, for all of the special reasons expressed in the earlier-filed, referenced patent applications.
Described and set forth, inter alia, in these earlier documents is a unique manufacturing technique wherein, in certain instances, etchable walls, or stripes, that are "laid down" during the explained thin-film deposition and patterning processes, are used to define the lateral boundaries (dimensions) of the final structures. In all instances, an ablation process(es) is (are) employed to give final lateral boundary definition to the final structures.
Further explaining, in addition to the special technique of using etchable walls or stripes to aid in defining the lateral boundaries of final micro-flexure body structures, we also recognize that, as just mentioned, other ablation, or etch-like, processes are usable and may be employed where desired.
For example, discussed herein specifically are two other ablation/etching-type approaches to the formation of flexure bodies - one of which employs a focused, high-power-density laser beam, and the other of which employs a reactive-ion etch using a plasma. All of the etching techniques employable in the practice of the invention take place in a non-mechanical, ablating fashion, and can be viewed or thought of as involving the fluid-entrainment removal of material to provide the final desired topographical outline for a wide variety of flexure bodies. Such unique fabrication methodology has led us to recognize how readily it lends itself to simple and easily controlled fabrication of micro-flexure structures with bodies having not only uniform cross-sectional dimensions, but also with graduated and changing cross-sectional areas and lateral dimensions along their lengths. Both simple and complex shapes are easily attained. Micro-flexure bodies can thus be uniquely designed to offer, readily, a wide variety of desired mechanical spring characteristics, resonance characteristics, dynamic-reaction characteristics, etc., to suit different specific systems applications.
Clearly as important as uniform dimensionality, among different, desired, cantilever flexure bodies usable, for example in a read/write setting, is a body which exhibits a graduated, or tapered, lateral configuration, and accordingly a graduated cross-sectional area progressing, generally, from larger adjacent the mounting end toward smaller adjacent the read/write, head-carrying end. Given the etchable wall/stripe and laser and reactive-ion fabrication technologies expressed herein and in the above-referenced prior documents as available manufacturing technology, an infinite variety of graduated/tapered configurations are easily and inexpensively possible.
Accordingly, the present invention proposes several unique, different generic forms of a flexure body, including tapered bodies, in a structure of the type generally outlined above, with some of these bodies including, and some not including, mass-reducing and dynamic-performance-differentiating, through-body void spaces. The special kinds of different performance enhancements which are achievable through such graduated topographics will be discussed in detail in the descriptions presented below.
Plainly among the important advantages offered and attained by the present invention are that flexure topography can be controlled with infinite variety, and that the same can be fabricated in a fashion which allows for very closely controlled fine-tuning of mechanical performance specifications. Similarly significant is that all of this can be achieved with great manufacturing simplicity, and in particular, with a manufacturing approach which does not require expensive, tricky, and potentially low-yield-producing and damaging machining operations.
These and other important objects and advantages that are offered by the present invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.